THE CORLISS ENGINE. 

By JOHN T^HENTHORN. 

Management of the Corliss Engine 



By CHARLES D. THURBER. 



Uniform in One Volume ; Price, $1.00. 






PR 13 1891' 



EGBERT P. WATSON. 



//rv 



This work is a republication of two articles which were 

first published in The Engineer, New York. They 

are wholly practical in character, being 

r intended as a guide to the most 

if economical management of 
^^i 1 j the Corliss Engine. 

COPYRIGHT BY EGBERT P. WATSON & SON, APRIL, 1891. 

150 Nassau St., N. Y. 



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4-S5" 



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TABLE OF CONTENTS. 



Chapter I. — Introductory and Historical. Steam 

Jacketing 

Chapter II. — Indicator Cards 8 

Chapter III. — Indicator Cards continued. The 

Governor 14 

Chapter IV. — Valve Gear and Eccentric. Valve 

Setting 18 

Chapter V. — Valve Setting continued, with dia- 
grams of same. Table for Laps of Steam Valve. 20 

Chapter VI. — Valve Setting continued 27 

Chapter VII. — Lubrication, with diagrams for same 30 
Chapter VIII. — Discussion of the Air Pump and its 

Management 36 

Chapter IX. — Care of Main Driving Gears. Best 

Lubricator for same 39 

Chapter X. — Heating of Mills by Exhaust Steam . . 44 
Chapter XI. — Engine Foundations ; diagrams and 

templets for same 48 

Chapter XII. — Foundations continued. Materials 

for same 53 



THE CORLISS ENGINE. 



CHAPTER I. 

Since the issue of the patent, in the year 
1849, to Geo. H. Corliss, for certain improve- 
ments in the working of steam-engines, and 
covering the admission of steam to the cylin- 
der by the combined action of a governor, to 
determine the point of cut-off at which a lib- 
erating valve-gear shall act, and thus allow a 
certain amount of expansion to take place in 
the cylinder before the end of a stroke is com- 
pleted, I think it will be conceded by all fair- 
minded engineers, when we come to look 
over the ground carefully, covered by the 
proposition, that no improvement has been 
made since that time, up to this date, in the 
economy of working steam expansively as ex- 
emplified by this system. This assumption 
may be questioned even now by a few zealous 
persons. 

The gradual development and appreciation 
of the Corliss system during the past thirty-six 



years, has grown to such proportions as to 
trace this Corliss principle in the design and 
build of a large proportion of the engines used 
in our manufacturing industries in this and 
foreign countries, and I may say that its use 
for maritime purposes is better appreciated to- 
day, and will be still better in years to come, 
by the few years of experience that it has 
been subjected to to determine its value over 
other systems now in use for that purpose. 

During this long period of increasing useful- 
ness, it has seen the rise and fall of the most 
sanguine expectations of many inventors for 
its honors. Sufficient evidence has been gath- 
ered by steam-users throughout, I may say, 
the civilized world, as a criterion of its merits ; 
and this has been established by facts cover- 
ing economical performance for years, rather 
than by claims based upon theory. 

STEAM-JACKETING. 

When we consider the value that steam - 
jacketing the cylinders of an engine offers for 
economizing fuel, we enter into many prob- 
lems of an interesting character. The mere 
fact of steam-jacketing a cylinder, or, in other 
words, subjecting the working barrel to a con- 



stant circulation of steam direct from the 
boiler, inclosed in a separate chamber, does 
not imply a direct or definite saving in fuel 
equally available to all types of engines. 

In one case it is an improvement of a very 
decided character, while for another, working 
under a different range of expansion, the addi- 
tional expense for its provision would not be 
justifiable when we consider the question of 
fuel and care necessary for the proper working 
condition of the jacket. Steam-jacketing is a 
decided advantage when a liberal amount of 
expansion is carried out in the cylinder, or 
when a wide range in temperature exists be- 
tween the initial temperature of the steam ad- 
mitted and the final temperature at which it is 
exhausted into the condenser or atmosphere. 
Therefore its economical application is gov- 
erned entirely by these two elements. 

To steam-jacket a slide-valve engine, when 
the steam is allowed to follow nearly full 
stroke before cutting off, the saving in fuel, for 
this case, would not pay the difference for the 
extra cost of such practice, and is not advisable. 

The shorter the cut-off in any engine, the 
more efficient a system of steam-jacketing the 



cylinder becomes ; from the fact that the 
amount of cylinder condensation which takes 
place at each admission of steam to the cylin- 
der is reduced to a minimum, by maintaining 
the walls of the cylinder at a uniform temper- 
ature. 

Many people suppose that this question of 
admitting steam to a cylinder to overcome a 
given amount of resistance is like unto meas- 
uring beans in a bushel, and of a practically 
definite quantity, whereas, the fact is, that 
when steam is admitted to the cylinder suffi- 
cient heat has to be imparted by such entering 
steam to the walls of the cylinder to bring its 
temperature up to a point equal to that of the 
entering steam, resulting in a possible amount of 
cylinder condensation equal in quantity to that 
required to overcome the work of that stroke. 

It is therefore essential that when we con- 
sider the question of the economical perform- 
ance of any proposed engine, we thoroughly 
consider the effect that an efficient system of 
steam-jacketing offers for that purpose. Its 
application is well worthy of the object, and 
may safely be stated to save, for engines of 
approved character using steam expansively, 



from 8 to 10 per cent, of the fuel used. It 
may be claimed by a few that the speed of 
the engine has a marked influence upon the 
amount of cylinder condensation, from the 
theory that the walls of the cylinder are ex- 
posed for a greater length of time between each 
alternate stroke of the engine, for strokes of 5 
to 6 feet, and about 60 revolutions per minute, 
and consequently more condensation takes 
place during that period than would otherwise 
occur for a higher speed of rotation and shorter 
stroke. This assumption, although existing as 
a fact for slow speeds, ceases to have much 
importance for what may be termed long-stroke 
stationary engines, say from 5 to 6 feet, or 
considering other circumstances of equally 
practical moment for speeds even as low as 50 
to 60 revolutions per minute. 

At this speed, I believe, for equal points of 
cut-off or range of expansion, that the differ- 
ence in fuel, due to cylinder condensation be- 
tween this speed, of say 55 revolutions per 
minute, and for engines of a higher speed of 
rotation, say 100 revolutions per minute, a 
jacket is of no practical value, as I believe, for 
the disadvantages attending such a high speed 



8 



of engine more than neutralize any benefit to 
be derived from an assumed decrease in the 
cylinder condensation in the working of the 
two systems. 



CHAPTER II. 

INDICATOR-CARDS. 

I do not consider that the engine making the 
finest-looking indicaior-card, as that term is 
generally considered to-day by engineers, is 
•necessarily working to the best advantage, re- 
garding friction and economy. 

I am aware that this impression has been 
given by some engineers, who have suggested 
to manufacturers that such must necessarily be 
the case under all circumstances. I am free to 
admit that I think there are other conditions to 
be fulfilled, in the satisfactory working of an 
engine, equally as important as giving an indi- 
cator-card : "fulfilling all the conditions neces- 
sary for economy " with their square corners, 
excessive compression, and plumb-line induc- 
tion, representing the admission of steam to 
the cylinder. 

To my eye, the best-looking card is that show- 
ing the least amount of fiictional resistance to 



be overcome for a given amount of work per- 
formed, and compression sufficient to gently 
affect the moving parts as they come to rest; to 
turn the center with an expansion-line follow- 
ing well-established rules, and. a movement of 
the exhaust-valves to allow in the least possible 
time, during the first part of the return stroke, 
the piston to have the full benefit of the vacuum 
where a condensing-engine is employed. 

If these conditions are fulfilled, I believe that 
the engine is accomplishing good work eco- 
nomically, with a minimum amount of friction 
for the power developed. All these conditions 
may be obtained, notwithstanding we may 
have a card where the steam-line falls off as in 
Fig. i. To some, this may seem a very serious 
delect. If we wish to drive machinery econom- 
ically, assuming we have tools to do it with, we 
should so adjust its condition of working that it 
may be able to produce that result with as little 
effort to move itself as possible. This implies 
an admission of fullboiler pressure to the cylin- 
der after the crank has passed the center to help 
turn the crank-shaft rather than retard it. This 
will be the case if we attempt to make a per- 
fectly plumb steam-admission line on the card. 



10 

To bring about this early admission of steam, 
or steam-lead so called, to produce a steam-ad- 
mission line at right angles to the line of mo- 
tion it is necessary to so place the eccentrics 
relative to the crank as to have the steam- 
valves which are operated by it in such a posi- 
tion that boiler pressure may be upon the 



Fig. i. 

piston the instant the direction of motion is 
changed. To accomplish this implies an open- 
ing ot the steam-valve before the crank comes 
up to the center, as shown in Fig. 2. Now any 
such steam pressure admitted to the cylinder 
with the crank in that position is a detriment, 
causing an increase in the friction of the en- 




Fig. 2. 



12 

gine by a longer application of pressure upon 
crank and cross-head pins, and main bearing ; 
also, a diminution in the energy of the wheel, 
which, necessarily, has to be restored by addi- 
tional steam at the next stroke of the engine, 
and a generally debilitating effect upon all 
parts of the engine. 

I believe that the time to admit full steam 
pressure to an engine, leaving aside the ques- 
tion of handsome indicator-cards, is when the 
crank has arrived at such a point in its travel 
(see Fig. 3) as to be influenced by such press- 
ure, with the effect, as I have said before, to 
momentarily hasten rather than retard the ac- 
tion of the driving pulley. 

Of course, I do not wish to be understood as 
favoring extremes, even in this direction ; but 
I am willing to accept Fig. 1 as a basis for my 
indicator-card. That, in my judgment, is best 
suited for the majority of engines as ordinarily 
run, producing the least triction in cccomplish- 
ing a given amount of work, and in the easiest 
running condition, all things considered, for 
doing that work. 




Fig. 3. 



14 



CHAPTER III. 
I have seen, a great many times, the folly 
and evil effect of allowing a fine-looking indi- 
cator-card to be the ruling spirit governing 
valve adjustments, where questions of a prac- 
tical character have not been considered af 
sufficient importance to justify thought, so 



Fig. 4. 
long as a "fine-looking " card, as shown in Fig. 
4, is obtained. This state of affairs requires 
adjustment, so that the engine may show an 
indicator-card worthy of consideration, and be 
given a chance to do its work, untrammeled 
by steam-lead or the excessive compression 
that is now "fashionable." High compression 
is assumed to be a necessity for all high-speed 



i5 

engines, from the fact that it is much used in 
locomotives. 

If we compress steam in the cylinder by an 
early closing ot the exhaust-valve, up to a point 
about equal to the terminal pressure, we have 
reached the limit desirable for condensing-en- 
gines; for the majority of non-condensing en- 
gines the compression should be about 5 lbs. in 
excess of the terminal pressure. These limits are 
suggested by a consideration of practical ques- 
tions equally as important to the manufacturer 
as those of a theoretical nature, and are applic- 
able for points of cut-off in the two systems best 
adapted for economy, coming within the range 
of about i-5th and i-7th cut-off, respectively. 

THE GOVERNOR. 

The function of a governor is to act in ac- 
cord with each variation of load, and to so limit 
the quantity of steam to be admitted to the 
cylinder as to overcome the resistance of the 
load, and thus maintain a uniform speed of ro- 
tation of the engine-pulley. This cannot be 
properly done unless the action of the gov- 
ernor is untrammeled by unnecessary friction, 
so as to instantly meet changes in the load as 
they occur from time to time. 



i6 



We should, therefore, see that all of the 
working surfaces of the governor are in proper 
running condition, and a quality of oil used 
for lubrication that will not " gum up" after it 
has been applied for a time. We should, also, 
see that the oil, or dash-pot, is in good work- 
ing order, with a constant supply of oil to gent- 
ly retard any sudden fluctuation in the move- 
ment of the regulator. 

On engines that have been speeded up to re- 
lieve their working, and bring about an earlier 
cut-off (by reason of an overgrown mill), we 
may possibly find that the speed of the regu- 
lator has been allowed to remain the same as 
before the change, with a possible chance for 
the overseer of weaving to suggest that the 
speed is not quite so uniform as before the en- 
gine was speeded up. 

To anticipate any such complaint we should, 
while we are changing the speed of engine, 
change also that of the regulator, and to over- 
come the effect of a higher speed of rotation 
upon the elevation of the balls of the regulator 
(and its equivalent effect upon the point of cut- 
off), we should weight the regulator down (as 
shown in Fig. 5) until the requisite speed is at- 



17 




Fig. 5, 



i8 

tained for the engine. By doing- this we may- 
divide up the interval of time, which such vari- 
ation and speed of engine has upon the gov- 
ernor, and its consequent reaction upon the 
cut-off mechanism of engine, to a shorter de- 
gree, and thus control the point of cut-off dur- 
ing one revolution of governor in place of one 
and one-half revolutions, which would be the 
case if the governor was allowed to run slow 
on an engine that had been increased in speed. 
After this has been done, especial care should 
be taken to see that all bearings are kept 
thoroughly clean and free, for the lubricant to 
act, for this speeding up is attended with more 
or less risk, on account of imperfect lubrica- 
tion and non-adaptability of the engine and its 
parts for such a change in the speed. 



CHAPTER IV. 

In engines of this type having a detachable 
valve gear where the motion for working the 
valves is derived from the action of an eccen- 
tric, it follows that when there is no lap on 
the valve to be worked off or the steam valve 
set edge to edge with the port opening, that 
the eccentric will be at its half-throw, or at 



19 

right angles to that of the crank when it is on 
its center. 

During the rotation of the shaft, the eccen- 
tric would therefore arrive at its greatest throw 
and the opening motion of the steam valve 
would cease, and thus the detaching mechan- 
ism remain inoperative, while the crank or 
piston reaches, practically embraces, half stroke, 
and any liberation of the cut-off gear actuated 
by the governor or other means must take 
place, if at all, before this point is reached in 
crank travel, or before the eccentric com- 
mences its return stroke. If this action has 
not taken place the steam valve then com- 
mences to close positively at a speed governed 
by that of the eccentric. In order to have a 
safe working lap of the steam valve before the 
exhaust port upon that end is open to atmo- 
spheric pressure, or the condenser, and thus 
* prevent any blowing through during the rela- 
lative time of closing the steam and opening 
the exhaust valves, it is essential that the valves 
admitting steam to the engine should be given 
a definite advance in their movement relative 
to that of the exhaust. 

This is commonly called lap ; this and the 



20 

amount of it increases with the size of the en- 
gine. To neutralize this effect upon admission 
of steam to the engine, and have the valve 
gear in readiness to act for that purpose, when 
the crank comes up to the center, it is evident 
that the position of the eccentric must be more 
than 90 with relation to the crank ; or at 
a position beyond its center of half throw, in 
order to remove the lap given to the steam 
valve, and to take a position to admit steam to 
the cylinder. This ot course, reduces the range 
of expansion that steam may be carried for 
that end of the cylinder, by allowing less time 
during the travel of the eccentric before it 
reaches its full throw for the cut-off to act, 
which must occur, in this case, before half 
stroke is reached, or upon the opening motion 
of the steam valve. Occasionally, we may 
see an indicator card where the cut-off had ap- 
parently taken place after more than half stroke 
of the engine had been covered, which is a 
very bad condition, however, considered 
economically. At this point in the piston 
travel the velocity is at its maximum, while that 
of the valve-gear, actuated by the eccentric 
nearing its dead point of full travel, is at its 



21 

minimum. These elements, while working, 
as a matter of fact, with a positive ratio of ac- 
tion to one another, admit at this high velocity 
a certain amount of piston travel to take place 
after the point of detachment has been reached 
by the valve-gear before motion can be im- 
parted to the valve and its connection sufficient 
to cover a full port, and prevent further ad- 
mission of steam to the cylinder. This ap- 
parent cut-off taking place after half stroke has 
been reached is more prominently defined on 
the card as we increase the lap of the steam 
valve, and, by increasing this lap we are en- 
abled to open the exhaust valve sooner for the 
return stroke, thus giving a free opening for 
the exhaust in relation to the former, and nec- 
essarily enforcing a later closing of the valve, 
reducing the amount of compression; this may 
be considered by a few objectionable, and we 
will have something to say further on about it. 



CHAPTER V. 

SETTING VALVES. 

Upon the wrist-plate of the engine will be 
found three marks ; one representing the posi- 
tion at half-travel, or center of motion, while 



22 



the remaining two represent the extreme mo- 
tion of the wrist-plate as actuated by the ec- 
centric. 

Upon the wrist- plate stand, or pin, as the 
case may be, will be found a mark coinciding 
with those on the wrist-plate, designating the 
extreme motion and center of motion or travel, 




Fig. 6. 
as per Fig. 6. These are to be our guides in 
arranging for the relative time of action be- 
tween the four valves. 

Upon removing the back bonnets from our 
engine we shall see, also, a mark upon each 
face of the valve-port, showing the location 
and width of port openings in relation to the 
cylinder ; thus furnishing a starting point for 



23 

the setting of the four valves without the trou- 
ble of removing them from the port opening. 

Upon the end of the valves will be found, 
also, a mark in line with the opening edge of 
the valve, as shown by Fig. 7. 

In preparing to set valves the first operation 






UA 



1 *" . 

1 \ \ 





Fig. 7. 
is to place the wrist-lever at half-throw, which, 
for horizontal engines, is represented by the 
center of carrier and wrist-lever pin being 
plumb, but for the majority of beam engines 
the center of motion is represented by the 



24 

dotted and circular marks, as indicated upon 
Fig. 6. 

At this position, designated above, the marks 
on the wrist-lever and pin should correspond, 
and the whole mechanism be secured in that 
position, by placing pieces of paper between 
the washer on the end of the pin and wrist- 
lever, so as to produce friction sufficient to 
hold the whole in the desired position when 
the nut on the end of the pin is screwed up. 

This being accomplished, we may consult 
the annexed table giving the lap of the steam- 
valve, and the relative position of exhaust- 
valve when the wrist-lever is at its center of 
motion, and thus fix upon the lap for the 
steam-valve and the position of exhaust-valve 
desirable for the size of engine under consider- 
ation. 

By lengthening or shortening the connec- 
tions leading from this wrist-lever to steam- 
lever w T e bring the position of the opening 
edge of the steam-valve to correspond with the 
amount of lap fixed for that case, which, of 
course, should be the same for each end of the 
cylinder. 

For the position of the exhaust-valve, by con- 



suiting the table herewith we find for a 20" en- 
gine xVth of an inch opening. 

Table I. 

POSITION OF STEAM AND EXHAUST-VALVES WITH WRIST- 
LEVER AT ITS CENTRE OF MOTION. 



Size 


Laps of 


Exhaust 


of engine. 


steam valve. 


valve open. 


12" 


4 


1 // 

32 


14" 


5 " 
T6 


1 II 

32 


16" 


5 " 
16 


1 /' 

32 


18" 


3/' 
8 


1 // 
To 


20" 


3// 

8 


1 11 
T6 


22" 


3/' 
8 


1 // 

16 


24" 


7 " 

Te 


ft" 


26" 


7 " 

T6 


3 '/ 
32 


.28" 


7 " 
T6 


32 


30" 


1// 

■2 


1" 

8 


32" 


1" 
2 


1'/ 
8 


34" 


1" 
2 


1// 
8 


36" 


1" 
2 


*" 


38" 


9 " 
T6 


A" 


40" 


9 " 
T6 


3 II 
T6 


42" 


9 " 
T« 


3 // 
16 



This amount for each end of the cylinder is 
obtained by lengthening or shortening of the 
connection leading from wrist-lever to exhaust- 
arm, while the wrist-lever still remains at its 
center of motion, until we bring the marks on 
the end of the exhaust-valve to the distance re- 
quired from the closing edge of the exhaust- 
port. 



26 

We have now established the relative time 
desirable for the opening of the steam, and 
closing of the exhaust-valves, that each should 
act relatively to one another, and they should 
remain so without further adjustment being 
allowed upon the steam or exhaust connections 
until sufficient reason is established by practi- 
cal working to warrant a modification in ad- 
justment, and then only upon a full considera- 
tion of all the facts attending the working and 
the service for which the engine is used. When 
we change any one of these connections we 
alter its time of movement, and destroy the 
unison of action between the closing of one 
valve and the opening of another. If we 
shorten one steam connection, the effect is to 
allow that end to open quicker than its neigh- 
bor, but at the expense of a reduction in the 
safe working lap that it should have with rela- 
tion to the exhaust-valve. If we lengthen the 
connection, we increase the lap of the valve, 
with the effect of opening it later, which con- 
dition would call for a greater advance of the 
eccentric with relation to the crank. 

Again: if we lengthen the connection leading 
to exhaust-arm, we add lap to the valve, and 



increase the amount of compression at one 
part of its movement, while for the other part 
its time of opening will be later relative to the 
movement of the piston, and retard the exhaust 
to the condenser. 

If we shorten the connection, we increase the 
opening when the stud-plate is on its center ot 
motion, and consequently decrease the amount 
of compression thereby, with a corresponding 
earlier opening of the exhaust-port. 

This additional opening given to the valve 
by shortening connections reduces, also, the 
lap of the valve over the port that the exhaust- 
valve should have, during- the period of time 
coincident with that of the steam valve when 
upon the point of opening for the admission of 
steam to the cylinder. 



CHAPTER VI. 

SETTING VALVES CONTINUED. 

After we have "squared the valves," to use 
a shop phrase, it is necessary to look after the 
carrier and eccentric rods, and see that their 
travel is equidistant from an established center 
line of motion ; giving our attention first to 
the rod leading from eccentric to carrier-arm, 



28 



and termed the eccentric-rod. This rod is the 
rlrst acted upon, and after it is once adjusted 
will not be affected by any future adjustment 
found necessary for the carrier, or rod leading- 
from carrier-arm to wrist-lever. This might 
be iound necessary if we should reverse the 
operation, and thus make it necessary to go 
over the work a second time. 

After we have found that the throw of the 
carrier-lever is equidistant from an established 
plumb-line, in its extreme travel each way, 
brought about by adjustments in the length of 
the stub end, in the end of the eccentric-rod, 
until such a result is accomplished, we may 
repeat the operation of turning the engine by 
hand fo 1 * the benefit of the carrier-rod, or the 
connection leading from the wrist-lever to the 
carrier-arm, and so adjust its length that the 
wrist-lever will travel the same amount each 
way from the center of motion fixed by the 
marks upon the wrist-lever and pin. 

As we now have the valves adjusted rela- 
tively to one another, and also the throw of 
the carrier-arm and wrist-lever equally divided 
from center of motion, we place the crank 
upon one center or the other, and roll the ec- 



2 9 

centric around on the shaft in the direction 
that the engine is to run, until we bring the 
opening edge of the steam-valve on that end 
of the engine that is next to take steam, 32 of 
an inch beyond the line on the valve face rep- 
resenting the opening edge of the port, and 
secure the eccentric in position. 

It is well then to bar the engine around to 
the other center, and note if a similar opening 
is obtained, which will be the case if the rods 
are properly adjusted. 

After satisfying ourselves of the correctness 
of the movements, we may replace the back 
bonnets, and proceed to adjust the cam-rods 
leading from governor to the detaching levers 
on the valve-gear. 

In adjusting these cam-rods we should first 
block the regulator up to its extreme point of 
travel, and secure it for a time in that position. 
Then lengthen or shorten the rods leading 
from the governor to the valve-gear on each 
end of the cylinder so as to bring the detach- 
ing apparatus into action, and allow the valve 
to be unhooked with the regulator in that po- 
sition, when we roll the valve around by 
means of a starting-bar placed in the wrist- 



3° 

lever, until the steam-port is uncovered about 
^th of an inch. This adjustment will prevent 
the engine getting beyond the control of the 
governor if the load is suddenly removed 
from it by breaking a shaft or belt in the mill, 
or by extreme variation of the lnad, as in roll- 
ing-mill practice and similar service. 

After the adjustment of cam-rods has been 
made, we may lower the governor down to its 
lowest position, to see that the valve-gear will 
not be detached at that level. In this position 
of the governor steam should follow full stroke, 
and the valves should not be liberated until 
the governor has reached an elevation corre- 
sponding to nearly the normal speed of the en- 
gine and the load carried. 



CHAPTER VII. 

LUBRICATION. 

The question, which is the best method of 
lubricating crank and cross-head pins of en- 
gines running continuously is not positively 
settled in my mind 

There is one thing certain: a plan must be 
devised that will admit of putting any amount 
of lubricant at pleasure upon the crank and 



3* 

cross-head pins, while the engines are running 
at their regular speed; either by first dropping 
it upon a ribbon of canvas and, in turn, taking 
off at each revolution by a wiper, secured to 
the mouth of an oil-cup on the crank end of 
the connecting rod, and also for the cross- 
head, as shown by Fig. 8. 




Fig. 9. 
This, I think, is a good plan; probably equal 
to any yet introduced for that purpose, al- 
though, in being exposed to all the dust in the 
room, it is, I think, more destructive to the 
bearings than the oil-pipe having its opening 
in line with that of the main shaft and con- 



33 

nected to the crank-pin, as in Fig-. 9. When 
engines are required to run only 11 or 12 
hours per day, with an interval at noon of 10 or 
15 minutes to fill up the cups, I think the most 
satisfactory method of lubrication for moderate 
speeds is oil cups, and they should be of a 
sufficient capacity to run all day with good feed. 
Main and back bearings, may be lubricated 
by cups having a sight-feed, and should be 
protected by glass casing around them, to pre- 
vent the dust from working down into the 
bearings. Or we may employ grease in boxes 
on the main bearings, having covers to pro- 
tect them. In many cases this is an excellent 
lubricant for heavy journals, although this 
method is more expensive to maintain than 
with oil, from the fact that the drippings from 
those journals cannot be used over again, and 
are, of necessity, thrown away. It is a most 
excellent plan to provide drip-pans under the 
crank, main and back bearings, eccentric, and 
end of slides, to catch all waste oil, not only as 
a means to promote cleanliness, but as a mat- 
ter of economy. Such drips should be after- 
wards strained through cotton-waste, and sets 
of sieves having bottoms made of wire-gauze 



34 

of different degrees of fineness, as shown by 
Fig. 10. After being passed through the strain- 
ers and removing all grit that may have been 
gathered, the oil may be used over again upon 
the heaviest of bearings, without any fear of 
trouble. This will materially reduce the oil ex- 



1^ WASTE (f 

I WASTE . / 




Fig. 10. 

penses. Cases may be cited where the waste 
oil from the hangers on line shafts of mills has 
been collected and treated in this manner, and 
afterwards used upon heavy journals that were 
subjected to high temperatures in inclosed 
engine-rooms; it worked quite satisfactorily. 



35 

This plan is certainly worth considering, 
where an. eye is had to the most economical 
method of lubrication. Another plan of 
lubricating bearings for heavy main lines of 
shafting is to provide rings made of iron or 
brass about ^ths of an inch wide, and i%ths 
thick, revolving upon the top of the shaft 
through recesses cored in the top and bottom 
shells, and of a sufficient diameter to reach 
from the top of the shaft to near the bottom of 
an oil cavity formed in the lower part of the 
pillow-block. This plan maintains at all 
times a constant and uniform oil-bath for the 
journals, as the oil is carried up by the revolv- 
ing ring, actuated by the shaft from the oil-pan 
beneath, using the oil over and over again, 
without any perceptible loss. It is needless to 
say that these rings and oil-pans should be 
protected from the dust, and a ring provided 
at each end for a bearing of moderate length, 
while for a bearing of excessive length one 
may be provided in the middle, and thus insure a 
uniform flow of oil throughout its entire length. 
As a matter of interest bearing upon this sub- 
ject, I would refer the reader to a paper pre- 
pared by the writer for the American Society of 



36 

Mechanical Engineers, and read at its meeting 
held at Atlantic City, May 28, 1885, wherein is 
contained a tabular statement of the quantity of 
oil used for cylinder and general lubrication in 
an engine-room, and for a number of mills. 



CHAPTER VIII. 

AIR-PUMPS. 

Trouble is sometimes experienced with the 
air-pump of the condensing apparatus con- 
nected to engines ; for it seems as though de- 
termined to make the most disagreeable noise 
possible by continual hammering of its valves at 
each change in the direction of motion. This 
state of things is most likely to occur where 
valves of large area are operating at a speed 
beyond their capacity and endurance. Within 
the past few years, in order to meet the de- 
mands of changes in the mill, it has become com- 
mon to speed up the engine, but in overcom- 
ing the want of power there is a possibility of 
encountering trouble in the air pump. The 
only remedy is in relieving the valves and pre- 
venting their hammering while working. 

Horizontal pumps are more susceptible to 
this complaint than vertical pumps having a 



37 

short stroke of the bucket, and a multiple of 
small valves for the discharge of the water of 
condensation. 

I have yet to see a long-stroke air-pump that 
will run smoothly to the satisfaction of the 
majority of engineers at, say, 55 to 60 revolu- 
tions per minute, w here there is but one large 
valve provided for the discharge of the water 
from the condenser. I may go still further and 
insist upon a number of small valves (in place 
of one large one), on the system first inaugurat- 
ed by the late Henry R. Worthington on his 
pumping-engines for Water-Works service. 

This plan is used by but few makers of air-, 
pumps, but it is correct both in theory and 
practice, and should be universal if satisfactory 
ends are to be accomplished. 

This plan of distributing a given area of dis- 
charge among a number of small valves in con- 
nection with a short stroke of the air-pump 
bucket as we increase the speed of the engine, 
will insure a most satisfactory and smoath-- 
running pump. 

For the ordinary speed of engines driving 
cotton-mills, from 60 to 65 revolutions per min- 
ute, we may safely employ pumps of 12-inch 



38 

stroke ; for 75 revolutions of the engine 10-inch 
stroke, and for 100 revolutions 7^-inch stroke 
should not be exceeded. 

In determining the proper capacity of an air- 
pump we may make it about ^th of the capac- 
ity of the steam cylinder, for ordinary condens- 
ing engines where the air-pump is single-acting. 

This proportion is ample and should always 
be provided for to meet the demands of a 
moderate increase in the speed of the engine, 
if such should occur from any cause. 

To relieve the hammering of air-pump valves 
I should recommend drilling into the space 
directly under the delivery-valve, inserting a 
%" pipe and valve, to be regulated at will for 
the admission ot a slight quantity of air under 
the delivery-valve. 

As this will be between the foot-valve and 
delivery-valve, and communication with the 
condenser is checked by the foot-valve and the 
water upon it, it will have no effect upon the 
vacuum in the condenser or engine. As to the 
regulation of the valve for the admission of air, 
experiment will soon demonstrate the best ad- 
justment for working conditions. 



59 



CHAPTER IX. 

CARE OF MAIN DRIVING GEARS. 

Gears, like all other parts of machinery, 
require looking after, to see that a proper 
bearing" is maintained throughout the length 
of the tooth and that they are working in 
their most advantageous positions regarding 
the pitch lines of one another. 

While advising a system of periodical in- 
spection we should, at the same time, insist 
upon a thorough lubrication at frequent and 
stated intervals. 

I am willing to admit my preferences for 
gearing for the majority, and I may say all 
cases, for transmitting heavy powers to first 
movers in mills, on the ground of less revolv- 
ing weight, shorter main shafts, and the gen- 
eral compactness of engines, and, I think, 
when all things are considered, the first cost 
will be in favor of the geared plant. 

But to come back to my text : this matter of 
lubrication for gears is a very simple affair, re- 
quiring but a short time every other day for 
the work, which if carried out, will reduce to a 
minimum any liability to abrasion, or teeth 



40 

getting out of shape ; resulting in a most satis- 
factory record, as to working, for a long term 
of years. 

This, of course, upon the assumption that 
the gears were properly made and propor- 
tioned to the work to be performed in the first 
instance. My experience leads me to believe 
that the most satisfactory method of lubricat- 
ing any gear is to apply the lubricant to the 
driving side of the tooth by a paint-brush, as 
the gear is moved slowly around by hand. 
This method insures placing the grease where 
it will do the most good, and not on the ends 
of the teeth, where, it is more than likely, 
the greater portion will be wasted if applied 
during working hours by p oaring it on. The 
proportion of the mixture which I have found 
to give good results is as follows : 

One pint of Carolina pitch-tar ; one pound of 
plumbago, four pounds of tallow ; melt to- 
gether and thin down with one pint of raw 
linseed oil. 

In the course of their journeys many, no 
doubt, have seen gears where the utmost care 
has been taken of them, and others so bad that 
if any quantity of grease should be applied 



41 

several times a day, it would be fruitless to 
remedying defects of construction; and to 
hope for smooth running gears, under such 
conditions, would be useless. Then again, we 
come across gears which have been in con- 
stant service for many years, with no percep- 
tible wear upon the surfaces of the teeth, not 
even upon those of the jack-shaft-gear, which 
is, of course, exposed to the most wear. I 
well remember a set of gears, which have 
been in constant operation for the past seven- 
teen years. The wear is scarcely perceptible 
upon the teeth, notwithstanding the fact that 
they have transmitted about seven hundred 
horse power for the first five years and about 
fourteen hundred for the remaining twelve ; 
they are doing excellent work to-day. 

Gears with wood and iron teeth working to- 
gether are a very good institution, where the 
noise of iron gears would be objectionable in 
a room, and it is surprising, sometimes, what 
an amount of power they will transmit without 
interruption, if properly proportioned to the 
work done, for a great number of years with 
but little wear. 

I remember an instance where, in the yea*r 



42 

'i8 : 47» there was a steam plant put into a cotton 
mill having for its driver an internal gear with 
wooden teeth. This gear was 12 feet diameter, 
working into one of 4 feet, the smaller having 
iron teeth. Each gear had a 10 inch face, and 
3.14 inches pitch. 

Since they were first started there have been 
put into the large gear less than a half dozen 
new wooden teeth, and this was only brought 
about by repairs to a segment, broken by 
bricks falling from a part of the foundation. 
Up to this date the original wood is running in 
the same gear, and has been in constant ser- 
vice; it is driving to-day about 170 horse 
power, at 72 revolutions of engine. This, I 
think, is a hard record to beat, and speaks well 
for the management, as well as for the lifetime 
of gears having wooden teeth. 

The wood in this case was hickory, and 
confirms the opinion that it is quite a difficult 
question to answer, as to what is the lifetime 
of wooden gears if proper care is taken of 
them while in operation, and well propoi- 
tioned in the first instance. 

Foundations for Gears. — There have been 
many excellent gears ruined when first started 



43 

by being placed upon shafts much too small 
for the requirements, or from being fastened 
upon timber work subject to shrinking and 
swelling, and, consequently, getting out of 
line from being fastened to such unstable 
work. .If the locality is such as to make it 
necessary to support gears on, or from timber 
work, the bearings for the gears should be first 
secured to a heavy cast-iron plate, and entirely 
independent of such wood-work. This plate 
should be, in turn, fastened to the timbers by 
bolts independent of those for the bearings; 
admitting of a slight adjustment of the gears 
without disturbing the alignment or level of 
the foundation plate. This same plan may be 
adopted when it is necessary to remove one or 
both gears, for repairs to them, or shafting. 
What is still better, and I think the only proper 
way, is to provide a good stone and brick 
foundation of ample weight, when the condi- 
tions will admit of it. 

In that case the bearings may be placed di- 
rectly upon the stone, properly dressed off, 
and securely bolted to the bottom stones in 
foundation. 

If this plan is carried out we may rest as- 



44 

sured that, with gears of proper dimensions, 
suitable to ■ the work to be done, they will run 
smoothly with a minimum cost for repairs, fric- 
tion and maintenance for a long term of years. 



CHAPTER X. 

HEATINQ MILLS. 

In the majority of cotton manufactories, 
•steam for heating and drying purposes is re- 
quired in more or less quantities in the different 
departments. To supply the heat for this work 
necessarily involves an expenditure of money, 
or, its equivalent, coal, and it becomes a ques- 
tion: as to the best method of supplying the 
heat in the most economical manner. If a 
limitqd quantity of steam is required, at inter- 
vals only, not equal to what would be dis- 
charged on one exhaust of the engine, the most 
economical plan would be to heat with steam 
direct from the boilers, and to run the engine 
condensing. Upon the other hand, if we have 
use in the different departments for all the ex- 
haust steam that would be discharged from the 
engine, we may divide the exhaust-chest into 
two independent chambers, as in Fig. n, mid- 
way between the two ports, and ?o arrange 



45 



our conditions of running as to be able to ex- 
haust from one end of the cylinder direct into 
the condenser, while, for the other end, the ex- 
haust may go to the heating pipes in the mill. 








... 






I 1 4 



Fig. 11. 
Or, we may run wholly condensing or wholly 
high pressure, as required by the varied condi- 
tions of the seasons. 



46 

In the event of having use for all of the ex- 
haust steam from the engine, we should, by 
all means, avail ourselves of the advantages 
whieh a non-condensing engine offers over a 
condensing, or even a compound engine, for 
similar work, from the fact that we are able to 
utilize to better advantage the heat in the steam 
passing from the cylinder after it has done its 
work ; it is equally as available for heating 
purposes. 

Woolen mill having dye-houses attached 
would come under this head, and for that, and 
similar service, the best compound system or 
condensing engine that could be devised, 
would prove inferior to a plain non-condens- 
ing engine ; all the conditions being taken 
into account. 

In one case we have a plant for driving ma- 
chinery only, with an expenditure of money 
for fuel for that purpose ; in addition we have 
that required for generating steam in sufficient 
quantities to meet the demands for heating 
purposes direct from the boilers, whereas in 
the other case we install a high pressure en- 
gine, and while we are running our machinery 
and using steam expansively for that purpose, 



47 

we are discharging sufficient exhaust steam at 
a pressure of from i^ to 3 lbs. in cotton mills, 
and from 4 to 8 lbs. for woolen mills. This is 
available for heating water, drying, etc., etc. 

In heating by live steam we accomplish but 
one result, with no benefit to be derived from 
its expansive force, but by first putting the 
amount of steam required for heating purposes 
through an engine, we derive benefit from its 
expansive force. We shall find that, for the 
same fuel, we are enabled to not only heat, but 
to furnish a certain amount of power. This, at 
first sight, mar appear strange reasoning, but 
it is attested by well established facts and con- 
firmed by the experience of manufacturers who 
have established the ecouomy of using ex- 
haust-steam over live steam for heating pur- 
poses, both in woolen and cotton mills. 

The whole secret of using exhaust-steam 
successfully is to provide ample main-pressure 
lines, and it is then available a long distance 
from the source of supply. 

In the ordinary construction of cotton mills 
it is well to first carry the main exhaust line to 
the upper room as soon, and in as direct line 
as possible, and there locate a back-pressure 



48 

valve under the roof, admitting of a change of 
pressure at will. 

From this point, we run to the center of the 
mill and across to each wall. Thus, in the 
upper story we have two main lines for the 
distribution, descending from this point to the 
basement. From these upright lines we 
branch off to each end of the mill, and with a 
system of piping on each side of the room as 
we descend, a uniform reduction in the size 
may be made, after each heating system has 
been provided for. 

The drip from the circulations should also 
return to the basement, where it should be 
trapped and collected in a tank for feeding the 
boilers. At the upper end of each drip-pipe 
means should be provided for blowing out any 
air that may be in the pipes. 



CHAPTER XI. 

ENGINE FOUNDATIONS. 

In dealing with this subject the probabilities 
are that a practical mason would be the most 
proper person to give advice, regarding the 
best way and plan of preparing an engine 
foundation, and to consider the most econom- 



49 

ical and satisfactory method of treating each 
individual case, so that in the end it will be the 
most suitable, and cover all the requirements 
to which it is to be subjected wnen finished. It 
is this knowledge of a full understanding of 
the necessities of the case, that first prompts 
me to hold my peace regarding this subject for 
abler hands, but upon reflection suggestions 
may be in order, covered by an experience 
sufficient to form an approximate judgment 
upon the subject. 

In preparing a bottom for foundations of en- 
gines many different characters of material 
are to be met with, and each requiring for 
their treatment quite a different mode of op- 
eration, so that one plan of a successful char- 
acter, carried out at one place, and in one 
material, may be quite inadequate to meet 
demands when carried out in a material of a 
different character in another locality. 

The easiest solution of this problem, next to 
rock foundation, is when a general bottom is 
found, below the surface. This state of things 
being established, we may excavate about 18 
inches below the bottom of engine foundation, 
and after being leveled off it should be 



50 

thoroughly sprinkled with water, and well 
tamped down with a heavy beater. This be- 
ing done, fill in about 3 inches in depth of the 
same material (gravel), and honestly repeat 
the operation, until there is a thoroughly com- 
pact mass of about 18 inches deep. Upon this 
base we may commence directly, without any 
further material, the brickwork of our founda- 
tion laid in good cement. 

The width of base should be from 2 to 3 feet 
more than the width and length of the engine 
foundation proper, as shown by Fig. 12. 

This foundation, or base, we may carry up 
about 5 courses in height before we come to 
the pocket-hole under the bottom stones, for 
the nuts and washers of the foundation-bolts. 
The absence of heavy footing stones, upon 
which to start our brickwork, may be looked 
upon with some distrust by a few, but facts 
have proven this arrangement to fully with- 
stand the vibration, and to cover all of the re- 
quirements for that purpose. 

Hard-pan, or clay-bottom, may be treated in 
the same manner. The most troublesome of 
all material to deal with, and to sustain a 
foundation upon, is quick-sand impregnated 



5i 

with springs of water, It is here that consid- 
erable thought should be given to the situation, 




Fig. 12. 



52 

and means provided to safely accomplish, in an 
economical manner, a first-class piece of work. 

The most successful method of dealing with 
this class of material, quick- sand, that has 
come to our notice is that devised by Mr. Geo. 
H. Corliss for the bottom of the foundation for 
one of his pumping-engines, and its building 
upon the bank of a river. This plan consisted 
of driving down any amount of stone, or 
other material, of small size, where required 
by the lines of the building and space covered 
by foundation of engine, by a weight in shape 
of a ball weighing about 4,000 lbs. falling any 
convenient distance, varying from 10 to 25 
feet. At each blow of the ball, rolling from a 
cradle upon which it had been hoisted, the 
loose stone, dumped from carts, were driven 
into the sand, spreading out as they descended, 
and finally making, as the work progressed by 
repeated addition of material and subsequent 
blows from the ball, a compact mass of 
sufficient solidity able to stand the test of 
years, without the least sign of settlement in 
any part of the building, or foundation of 
pump and engine. 

This plan of such a novel and successful 



53 

character is susceptible of application to many 
localities where similar material is to be con- 
tended with, and may be applied with the 
assurance of affording an economical and, 
at the same time, a successful means of 
producing foundation for almost any construc- 
tion. 



CHAPTER XII. 

Another plan is to excavate to the proper 
depth required between and under sheet piling, 
driven down as the excavation progresses un- 
til the depth is reached, where a bed of con- 
crete, formed by cement, sand, broken stone 
or brick bats, is placed ; the depth of same 
varying for each case to meet the requirements, 
usually from 24" to 36", and of such a dimen- 
sion of base as to present a large bearing sur- 
face upon the sand. Upon this bed of con- 
crete, after sufficient time has elapsed to allow 
the material to harden and settle, is commenced 
the brick work of the foundation. 

If this plan is properly carried out, and care 
taken not to cover too much space at a time, 
so as to allow the mass to harden while the 
process is in operation in putting down the 



54 

concrete bed, very good results may be ex- 
pected for most constructions. 

Crib-work, forming a heavy flooring made 
of timber, is sometimes resorted to in founda- 
tions, but as the bond between such material 
and cement is not of the best, and what would 
be desired for such work, we cannot consider 
this plan as efficient as those already referred 
to. Aside from the difficulty of getting an 
even and solid bearing for a timber platform 
upon the sand, any settlement of a part of this 
yielding material is likely to cause trouble in 
the foundation, from the lateral movement 
which may take place. 

MATERIAL FOR FOUNDATIONS. 

The most satisfactory materials, so far as 
my judgment serves me, to build engine foun- 
dations of, is a good quality of hard burned 
brick, well laid in cement mortar, composed 
of one part cement to one of sand, with plenty 
of water used upon the brick, and while laying. 

At the top, for the parts of the engine to rest 
upon, granite blocks of good size or iron plates 
may be bedded in cement, granite being by all 
means the most desirable. 

Similar blocks of granite should be provided 



55 

for the bottom and for the bearing surface of 
the foundation bolts. This is far superior to 
any wholly stone foundation that can be 
built, for equal cost. 

As a guide for the location of all bolt-holes, 
throughout the work of building the founda- 
tion, it is a very good plan to first prepare a 
wooden templet, carefully laid out from the 
drawings, and to cover all of the holes re- 
quired in the foundation. This templet may 
be made of one inch by six inch boards, as 
shown by diagram, Fig. 13, securely fastened 
together, and permanently suspended from the 
roof overhead. From this templet may hang 
at all times plumb-bobs over trie center of 
each bolt-hole. 

When the brick laying is commenced above 
the bottom stone short, wooden boxes, three 
inches square and about eighteen inches long, 
may be used to build the brick around, to 
form the bolt-holes, pulling the boxes up and 
centering them anew as the work progresses. 

Another plan to locate the position of bolt- 
holes in a foundation is first to establish the 
center line of shaft on the side walls of the 
buildings, by securing targets made of J4 



56 

boards six inches wide, and upon this plainly 
mark the position of shaft, relatively to walls 
of building. Upon the end walls of building 




Fig. 13. 



fasten similar targets, one to represent the cen- 
ter line of engine and one the center line of 



57 

back bearing. These two centers, of course, 
being exactly at right angles to that represent- 
ing center line of main shaft. 

From this center line of engine, measure off 
on the wall at each end of the building the dis- 
tance each way from this center that is required 
for the cylinder-foot bolts, and also, from this 
same center line of engine measure off the off- 
set for the main bearing. On the sides of the 
building w 7 e measure off an equal distance, each 
way fro n the line established for the center of 
the shaft, equal to that required for the holes in 
the main and back bearings. 

Also, from center of shaft we measure off 
the distance required to the first cylinder-foot 
bolt, and the distance between center of front 
and back cylinder bolts. 

From these different positions on target, 
where, it is assumed, nails are driven, we 
stretch stout lines, and at their intersection with 
their corresponding line we hang plumb-bobs, 
from w T hich we may work, throughout the 
whole height of foundation, for centering the 
piece of joist, or box, which we use to form 
the bolt-holes, a method already referred to. 



5« 



CHAPTER XIII. 
This plan will look something like Fig. 14. 
Of course these cross lines should be placed 

























5 


r~ 












































E-N-l 


RE 


-< 


>F- 


5H 










*c 


















































































1 

c 

i 

L 

c 


j 

J 

c 

J 








i 










z 








1 


r 
J 




































, 


' 













Fig. 14. 
high enough to be out of the way in walking 
round. If the location is such as to make it 



59 

inconvenient to carry out this plan, a substi- 
tute for the walls of the building may be had 
by building a fence, as it were, around the 
space to be occupied by the foundation, and 
upon which the various center lines may be 
marked and lines stretched accordingly, from 
side to side thereon. This plan is much more 
convenient, requiring less strength of line 
(which is an advantage) than when long and 
wide engine-rooms are to be met with. 

In bedding the top as well as the bottom 
stones down, in cement, it is a good plan to 
first lower the stone to its place to establish its 
level, and be centered each way, and after- 
wards hoisted up about three inches, and 
blocks put under each corner at that height. 

After mixing the quantity of cement required 
of the proper consistency, the operation of 
placing it under the stones, and leveling off 
the whole surface, should be done as expedi- 
tiously as possible, and the stone low T ered into 
position. A heavy wooden mall or piece of 
joist should be used endwise to bring it to a 
bearing and approximate level. 

In setting the top stones it is well to leave 
them about A of an inch high, so as to allow 



6o 

"bushing" down to a proper level all around, 
when the engine comes to be located. 

Above all things, in building an engine foun- 
dation, give no heed to the person who sug- 
gests economizing in the material to be used in 
it. It is very natural to suggest lime-mortar 
in place of cement, but if done, we shall have 
about as poor a foundation for the purpose as 
could be conveniently built. 

Aside from the extremely long time required 
for mortar to dry out, it will not stand the 
strain and jar to which it is subjected without 
cracking after a time, as the sand is not nearly 
so firm with lime as with cement-mortar. The 
difference in the benefit to be derived by the 
use of the best quality of cement will not 
allow, for a moment, a comparison between 
the two materials. Instances may be cited 
where engine foundations have been built in 
this manner (with lime-mortar) that became a 
source of annoyance and trouble when strain 
was put upon the holding-down bolts, by the 
mass giving way and settling; so that it was 
difficult to tell where the engine was, as to 
line. Resort had to be made to shims placed 
here and there, between the engine and stone, 



6i 

to make up for the deficiency caused by the 
stone taking a different level when the engine 
was screwed down. 

This is the result of trying to save the differ- 
ence between the cost of lime and cement, a 
very small item where so much depends upon 
the work for good running engines. 

As we approach the top of foundation, pieces 
of joist 4" by 6", should be built into the brick- 
work at regular intervals, where most conve- 
nient, to which we may fasten the floor-planks. 
And at the side of foundation, spaces should be 
left to receive the ends of the floor-beams, for 
the engine-builder is the most proper person to 
say where these floor-beams should be set so 
as to be least in the way of the exhaust and 
condenser pipes. These should be located 
from the plan furnished with that object in 
view, so as to readily admit making anew any 
joint about the engine coming under the floor. 

DRESSING DOWN TOP OF FOUNDATION. 

After allowing sufficient time for the founda- 
tion to season and dry out, we may commence 
the operation of "bushing'' the tops of foun- 
dation-stones to bring them to the proper level 
at the places covered by the machinery. To 



62 

do this . properly we should provide ourselves 
with a three-foot and a fourteen-foot straight- 
edge, and a good spirit-level. After satisfying 
ourselves as to the lowest place in the different 
stones that is to be covered by the bearing 
surface of our machine, we use that as a start- 
ing-point, from which we are to determine the 
proper level for the remaining portion of the sur- 
faces of the different stones in top of foundation. 

This is best done by providing short blocks, 
say two inches square, upon which, at differ- 
ent points, we rest the ends of our straight- 
edge, one block being located at the starting- 
point, while the other is set at that part of the 
stone to be worked upon, dressing down with 
the bushhammer until we reach the proper level. 

After a number of spots at the proper level 
have been established upon each stone, we 
may work off the surplus between these places 
to the best advantage, and finally, smooth 
down the work to a bearing by a judicious use 
of the bushhammer, using as a guide our short 
straight-edge, having one edge rubbed with red 
chalk, which being applied to the stone deter- 
mines the high places that are to be removed 



<>3 

MANAGEMENT OF THE CORLISS ENGINE. 



CHAPTER I. 

The cotton manufacturing company, by 
whom I have been employed for the past eight 
years, is located on one of the New England 
rivers, which furnishes very good water for 
steam purposes. We have one large battery of 
boilers in which the pressure is ioo pounds for 
the simple condensing engines, and in line 
with these there is a battery of six boilers, in 
which the usual pressure is 125 pounds for the 
compound engine. 

All of these boilers are return tubular, with 
overhanging fronts, and are 60 in. diameter, 
with 76 tubes 3^ in. diameter and 21 feet long. 
The distance from grate to shell of boiler is 24 
in. 

I am particular to give these dimensions for 
the reason that I have found them very good 
proportions, with the exception of distance 
from grate to boiler, which should be some- 
thing more, on account of the gaseous nature 
ol the Cumberland coal that we use. 

We have a small independent steam pump 



64 

connected to tanks, for weighing feed water, 
and other instruments lor testing the evapora- 
tive efficiency of the boilers, and trying differ- 
ent kinds of fuel. 

Numerous tests have proved that the 'best 
method of burning bituminous coal is the one 
mentioned in The Engineer of October 18, 1890, 
p. 90, " The Smoke Nuisance" as the slow-firing 
method. I allow but three shovels fall of coal 
to each furnace door at a time, and alternate 
from right to left hand door at each firing. 
This does not prevent all smoke by any means, 
but there is not an objectionable amount ap- 
pearing at top of the chimneys at any time. 

The method of coking the coal in front of 
the fire, I have found very objectionable when 
tried in connection with an evaporative test. 
The fireman cannot see the body of his fire and 
there are sure to be thin places where cold air 
rushes through ; and besides this it is very de- 
structive to the front of the furnace. 

Leaving the fire door open a little for a few 
moments after each firing reduces the amount 
of smoke, but gives a lower result of water 
evaporated on a week's trial. I have also 
carefully tried introducing air through perfor- 



65 

ated plates in the bridge wall. This appeared 
to promise success, judging by the appearance 
of the fife as seen through sight-hoies on back 
end of boiler, but I found by my testing ap- 
paratus that this view of the fire was very mis- 
leading. 

The best results will be found with moderate- 
ly thick fires, and while burning from 12 to 13 
pounds of coal per square foot of grate per 
hour. 

I have met many engineers who seem to 
think that slow combustion means more per- 
fect combustion. I have found the reverse to 
be true. A high firebox temperature, a clean 
boiler, and low temperature of uptake, is what 
is wanted. 

All engineers who possibly can should have 
apparatus for weighing feed water and making 
evaporative tests, as the amount of steam used 
for power and other purposes is liable to con- 
siderable variation, and the weight of coal 
alone does not always give a correct result. 

Bv careful trials one can readily find out 
what is best in any given case, and will un- 
doubtedly find the unexpected sometimes, and 
thereby make a handsome saving in the coal 



66 

bills. These tests should not be less than one 
week in duration. 

I have found it best to leave the air passages 
in furnace doors open at all times, while burn- 
ing bituminous coal. The draught is much 
better regulated by an automatic damper regu- 
lator than by hand. 

My experience with shaking grates has not 
been very favorable. By a careful trial of one 
week, of one of the best rocking grates in the 
market, I failed to find any gain in economy of 
coal ; in fact a slight reduction in pounds of 
feed water evaporated. This was probably 
owing to the reduced grate surface, as the 
maker put dead plates three inches wide on 
sides and back of furnace. 

We have for a number of years used plain 
grates in sections about 6 inches-wide and 21 
inches long, air opening y 2 inch, width of metal 
bars y 2 inch. I see no reason why they should 
not last ten years. 

In boiler rooms where there is shafting, the 
Davis double plunger feed pump has proved to 
be very reliable and durable ; 6 inch plungers 
should not be run over 25 strokes per minute. 
I would §ay avoid single plunger pumps, both 



6 7 

power and steam, on account of the pulsations 
of the water in the pipes, and especially so if 
you have a fuel economizer or large feed water 
heater, as all the water contained in these 
must come to rest at each change of stroke, 
and must be made to move on again as the 
plunger advances, while the duplex pump 
keeps the water steadily advancing all the 
time. 

. The feed pipe should not be less than two 
inches in diameter, and is best when made of 
brass, and introduced into the boiier on the 
top at back end over the steam space. Where 
the draught is sufficient the fuel economizers, 
so-called, are true to name. The reduction in 
fraught will amount to about 5-iooths of an 
inch of water, and at this mill heats the feed 
water from ho to 220 degrees. 

All valves on water pipes should be of the 
straight-way pattern. I use a gate- valve for 
both steam and water, and provide all steam 
valves over 3 inches with a ^ inch by-pass, 
by which steam can be let into the pipe with- 
out ^shock, which is very destructive some- 
times. 

The following is a copy of one of the many 



68 

tests that 1 have made : There was no special 
preparation made for this trial, and no allow- 
ance made for moisture in the coal. The coal 
includes that used to get up steam from pold 
water and banking fires : 

.Duration of test. r , 2 da y?- 

Boiler pressure in pounds IDI 

Temperature of feed in degrees 13° 

Temperature escaping gases 39 2 

Water evaporated in pounds 83,034 

Coal consumed in pounds 8,397 

Weight of combustible in pounds . • 7,891 

Coal per square foot of grate per hour 131 

Water evap. per pound coal, (actual conditions) 9,888 

Water evap. per pound combustible 10,522 

Water evap. per pound coal from and at 212. . . IM73 
Water evap. per pound combustible from and 

at2i2 .•■•••• • 11,889 

Percentage of water in steam °-5 

CHAPTER II. 
In the last chapter nothing was said about 
the quality of steam produced. This is a 
point too frequently overlooked by engineers. 
If you have upright boilers which moderately 
superheat the steam, you are all right in this 
respect, but with horizontal tubulars there is a 
strong probability of there being too much 



6 9 

moisture in the steam. This can be determined 
by the calorimeter test, which has been fully 
explained in engineering papers. I do not 
consider that high evaporative results from 
horizontal boilers are of any value, unless ac- 
companied with the calorimeter test, showing 
that the steam produced is quite dry. 

This tendency of horizontal boilers to fur- 
nish wet steam is the reason why I prefer well 
designed uprights when high steam is required 
for compound engines. One gauge of water 
while engines are running, and continuous 
feed, will prevent an excess ot water passing 
away with the steam in boilers of good design. 
1 depend entirely on gauge cocks, having no 
glass gauges whatever. These boilers in my 
charge are over 10 years old, and, all told, 
there are over 22 hundred tubes ; not one of 
them has ever leaked from any cause. 

We are all aware that properly covered pipes 
contribute largely to the economic results. I 
have found that hair felt, with asbestos mill 
board next to the pipe, makes a good cover- 
ing, but for a short time only. The asbestos 
does not prevent the felt from burning on top 
of pipe ; in 6 months it will be found nearly, 



70 

if not quite, destroyed, and on the bottom it 
will be hanging loose from the pipe. On 
flanged pipe I use one inch each of Nos. i and 
2 asbestos cement, and outside of this, one 
inch of hair felt. This brings the covering out 
even with the flanges ; then all is covered 
with heavy cotton cloth, and for the boiler 
room it is whitewashed; in the engine rooms 
it is covered with a jacket of Russia iron, and 
brass bands to break joints. 

In regard to the size of steam pipe to the 
engine, I would say : Do not be governed by 
the capacity of opening into the cylinder or 
the valve furnished by the builders. The high 
piston speeds now so common require larger 
pipes, and if they are long, considerably larger 
diameter should be used. The Corliss cross 
compound engine, of which I am about to 
write, has cylinders 22" + 40" by 60" stroke, 
and runs 60 revolutions per minute. The 
throttle is 7" and the steam pipe about 200 feet 
long. I enlarged from the throttle with a short 
piece of cast-iron pipe up to 10", and the bal- 
ance is made of 10" boiler tubing in long 
lengths, with heavy cast-iron flanges riveted 
on. All bends are made of copper. Such a 



7* 

steam pipe as this is far more reliable lor high 
pressures than cast-iron or common wrought 
pipe with screwed joints. 

The cylinders ot this engine are proportioned 
in this way on account of the unusual amount 
of steam required for use in the mills, which is 
taken from the receiver. Besides seven slash- 
ers (which turn off something over ninety 
thousand pounds of yarn each week), there 
are eighty vapor-pots in the weaving rooms, 
all of which are supplied from this source. 
The usual pressure in receiver is five pounds. 
This engine has been running two years, and 
is connected to ten water-wheels of 180 h. p. 
each. There are no regulators on the water- 
wheels, the engine governor controlling the 
speed of all. From this and other causes, the 
load is quite variable, and with full river the 
engine is sometimes underloaded. 

As left by the builders, I at first had trouble 
to maintain an even pressure in the receiver, 
and furnish steam for use in the mills, as the 
point of release on both cylinders was deterr 
mined by the governor, and no way was pro- 
vided to change the cut-off on l.p. cylinder. 
This would be correct under certain conditions, 



72 

but not so here, as the amount of steam taken 
from the receiver is subject to considerable 
variation, and this, together with changes in 
power required, made it necessary to make an 
alteration. The regulator shaft connecting one 




cylinder with the other was cut in two and 
connected as shown by sketch. 

By turning the nut between the levers to the 
right or left, the l.p. cylinder is made to take 



73 

more or less steam, as the case may be, and 
at the same time it is controlled by the regu- 
lator. 

During a large part of the time the l.p. cyl- 
inder is made to cut off somewhat earlier than 
would be the case if a low steam consumption 
by this engine alone was desirable. It is the 
total coal used that interests the stockholders. 
During the season of low river, when other en- 
gines are furnishing the steam for use in the 
mills, and this engine is running under favor- 
able conditions, the coal consumed during a 
test of one week, including that used for bank- 
ing fires at night, was 1.73 lbs. per h.p. per 
hour. 

The exhaust steam from the duplex feed 
pump on this trial was used to heat the feed 
water for another set of boilers than those from 
which the engine steam was taken. As run- 
ning at present — with an overflowing river, 
and steam taken from the receiver for the 
mills, as mentioned above — the coal used per 
h.p. per hour varies from 1.9 to 2. 1 lbs. 

The variations in load, sometimes caused 
the receiver pressure to fall quite low, un- 
noticed by the engineer. This made bad work 



74 

and loss in the slasher room. To prevent this 
loss, and give us timely notice, I connected a 
small whistle to pipe leading- to slashers, as 
shown by sketch. 

A pressure of 5 pounds nolds the valve down 
to its seat, but at 4^ pounds the weight lifts 
the valve, and blows the whistle before there 
is any cause for complaint in the mill, and the 




oz: 



engineer has time to make the proper adjust- 
ment of the cut-off on the l.p. cylinder, or 
open the by-pass valve into receiver. 

The air pump is the regular Corliss pattern, 
34 in. by 12 in. stroke. A part of the over- 
flow, with the water of condensation from 
the receiver, is returned to boiler room. A 



75 

Y^ in. pipe from the overflow leads up to the 
engine room, into which a thermometer is 
inserted, and returns below to condenser, thus 
showing temperature of overflow water at all 
times. 

A small pipe, admitting a little air into the 
channel way, effectually stops the pound that 
is so common with this kind of air pump. 

As the machinery in the mills is run at as 
high speed as possible, it is very important 
that the engine regulation should be as perfect 
as it can be made. 

This engine should make a full revolution 
each second; if it should tall short of x&n of 
a revolution in each second throughout the 
day there would be a very perceptible diminu- 
tion in product. If it should fall short this 
much during an hour it is so much lost; it 
should not be made up in the next hour. 

The Corliss governor, unaided, will not 
regulate as closely as it is desirable to run in a 
cotton mill. 

I have found the Gale governor attachment 
to be a great help, but even this useful and 
neat-looking little device needs some attention 
if a strictly uniform rate of speed is desired, 



7 6; 

I suppose the Moscrop recorder is an excellent 
thing to show the variations in the speed. A 
good many years ago, before I ever heard of a 
"Moscrop," or other device for this purpose, I 
made a little machine, which is still doing 
splendid service. On the shaft of the air pump 
rocker is fixed a small adjustable arm carryii g 
a ratchet, which picks one tooth at each rev- 
olution of the engine in a ratchet wheel of an 
equal number of teeth, with revolutions de- 
sired by the engine in one minute. On the 
shaft of this ratchet wheel there is a pair of 
mitre gears, by which this movement is taken 
up into the engine room, where, at a con- 
venient place, there is a clock dial with suitable 
train of gears to run a minute and "second 
hand." 

After the engine is started, the hands on 
this dial are set to exactly agree with the 
engineer's time. After an hour's run, if there 
is a gain or loss of one second, which means 
with this engine one revolution, it is easily de- 
tected and corrected. This dial makes no 
record of the revolutions for yesterday or last 
week, but as it enables us to run just right all 
the time; it is very satisfactory. The engine 



11 

register or counter shows each day the num- 
ber of revolutions, and this is recorded for each 
engine, with all other matter of interest, in a 
logbook kept for this purpose. 





These cards were taken November 4. There 
was not sufficient load for the engine to show 



7 8 

its best work. The cards from the other ends 
are as nearly the same as can be. Springs in 
indicators, 60 and 12 to the inch. 



CHAPTER III. 

The compound from which the indicator 
cards in the last chapter were taken is said to 
be Mr. Corliss's final and perfected engine. It 
certainly is very economical in the use of 
steam, and many parts are excellent in design, 
but there are others which are not quite per- 
fect. 

There is no means provided to raise the 
pistons as they wear below the center; the 
steam packing rings are let into the head, 
there being no bull-ring. The piston can be 
turned around on the rod, which will make up 
for the wear on the packing rings, but not for 
the wear of the cylinders. The slides are very 
much too narrow ; there is not sufficient bear- 
ing surface for heavy loads. The pillow blocks 
are all that could be desired, 24 in. length of 
bearing for an 11 in. shaft. The hand hole in 
the side, which enables the engineer to dis- 
cover any heating before it has pervaded the 
whole mass, is a very good thing. The shaft 



79 

is 15 in. in diameter in the center, and carries 
a 25 ft. wheel, weighing fifty thousand pounds. 

The valve gear is very peculiar, and different 
from any other Corliss engines made. The 
wrist plates are nearly as large as the sides of 
the cylinders, and the valve connections are, 
consequently, very short ; this gives the valve 
a very quick movement. The vacuum dash- 
pots close the valves very quickly, as will be 
seen by the cards. The piston rods have U. S. 
metallic packings, and the valve rods are 
packed with Garlock's patent sectional rings. 

This engine has run two years, and has been 
stopped but once during working hours from 
causes arising in engine room. One of the ad- 
justing screws on the cross head gibs worked 
loose soon after the engine was left by the 
builders, and it was necessary to stop. I have 
put preventers on all of these screws, as I 
found that they had a tendencv to work loose. 

I saw an item in the daily papers of an en- 
gine of this type running away and breaking 
up badlv ; the question has been asked, why 
the governor did not take care of it ? I should 
say that the cut-off rods were so set that when 
the governor balls were at their extreme height, 



8o 



the low-pressure cylinder would still take some 
steam as long as there was any in the receiver, 
and there would be enough (with the Vacuum) 
to do mischief. 

There are some features about another en- 
gine, in my care, which may possibly be of 
interest to engineers, who may have similar 
conditions. 

This is a double high-pressure condensing 
engine, having cylinders 26 in. by 60 in. stroke, 
running 58 revolutions per minute; built at the 
Corliss Steam Engine Co.'s Works, in 188 1. It 
can be run ^, y 2 , $£, or all condensing. 

During a few weeks of very low river in the 
summer we run all condensing, in order to get 
full power, some times as much as 950 h.p. I 
have never been able to test the steam con- 
sumption with this load, but it is not of these 
conditions that I am about to write. 

This engine runs in connection with six 
waterwheels of 180 h.p. each. Several years 
ago, during the season of high water, this en- 
gine was disconnected from the mill, the 
waterwheels doing all the work, the steam for 
the slashers and vapor for weaving rooms be 
ing furnished direct from the boilers. As there 



8i 

was not sufficient power in the wheels to 
insure good regulation, there was a diminished 
product in the mill. The slashers and vapor- 
pots were then piped for exhaust steam, and 
one cylinder only of the engine was run non- 
condensing, with five pounds back pressure. 
Sufficient water was taken from the water- 
wheels, to give the engine a load of ioo to 150 
h.p. The result was very satisfactory, perfect 
regulation and full product in the mill, and less 
coal consumed than was required to do the 
mill work with direct steam. The gates on the 
wheels were so regulated that there was very 
little, if any, steam escaped through the back 
pressure valve. 

For the past two years, owing to the en- 
largement of the mill, the load for one cylinder 
was such that there was about twice as much 
exhaust steam as the mill required. Besides 
this loss of steam, there were many days dur- 
ing the last part of the afternoon, when the 
river was somewhat low, that the load was far 
too much for one cylinder, while in the morn- 
ing one cylinder was ample. I then com- 
pounded this engine as shown by sketch. 

A piece of 2.0 in. pipe was placed in the ex- 



82 



haust from the high-pressure cylinder, which 
answers for a receiver ; from this we piped to 
the two-way valve on top of low-pressure 
cylinder. The throttle that was taken from 
this cylinder was placed in this new pipe. 
For more than two years this engine has run 



fc. / 






^ 


«/rA\ 




> )) 




sVM/ 


CO 








1_ 


o 






o 


H 






03 








o 

d 




n 




u 


jf-yin 






with this arrangement, giving perfect satisfac- 
tion. 

Besides running very economically with light 
load, one important advantage is that I always 
have the low-pressure cylinder connected, and 
ready for heavy loads, and the change is made 



83 



from compound to simple condensing, while 
running, and without any perceptible change 
in the speed. 

The amount of power derived from the low- 
pressure cylinder is quite small, from 60 to 90 





h.p., but this is obtained from steam that would 
otherwise be thrown away, and the 5 pounds 
back pressure must be maintained. When run- 
ning compound, with load of 400 h.p. or under, 



84 

and steam taken from the receiver for four 
slashers and twenty vapor-pots, the coal re- 
quired is 2.25 pounds per h.p. per hour. With 
one cylinder non-condensing, and furnishing 
the same amount of steam for use in the mill, 
and the other cylinder condensing, the coal re- 
quired is 2.69 lbs. per h.p. per hour. The cards 
shown were taken November 8, with light load. 
The springs used were 40 and 12 to the inch. 
I am aware that these are not perfect cards, 
but I think it will be generally admitted that 
the result, taken as a whole, is very good. 

As to setting Corliss' valves, I can add noth- 
ing to the full and correct article published in 
The Engineer, by John T. Henthorn, mechanical 
engineer, of Providence. 

When starting, as soon as the engine has 
made two or three revolutions, I raise the gov- 
ernor a little, by a thumb nut, in order to make 
the cut-off operate. This diminishes the liabil- 
ity to take water from the boilers and greatly 
aids the engineer in getting a vacuum. 

The noise from the dashpots was somewhat 
harsh, and this was remedied by bolting a small 
box-shaped casting over the outlet holes, and 
from this running a i}( in. pipe, with cock in 



§5 

it below the floor. All the principal parts of 
the engines in my care are oiled by stationary 
sight feed cups. The cylinder oil is introduced 
at each end of the cylinders. The oil for other 
parts I usually mix 3 parts paraffine to one of 
sperm, and one of neatsfoot. This mixture 
costs 32 cents per gallon, and will run the 
heaviest shaft and not gum. 

Usually a very small quantity of oil is suffi- 
cient for crank-pins and cross-head wrists, but 
my experience has taught me that main bear- 
ings should have a very generous quantity reg- 
ularly applied, carefully collected in drip pans, 
and strained and used again. With an expe- 
rience of over thirty years, I have never 
stopped an engine for a hot pillow-block. The 
cost of all the oil for the 26 in. double engine 
mentioned, including two jack shafts, is twenty- 
seven cents per day. The compound engine 
requires about the same quantity. A pair of 
23m. x 6oin. engines, running 66 revolutions 
per minute, are oiled for seventeen cents per 
day. 

Some experience with the indicator, together 
with my observation of the running of many 
non-condensing Corliss engines, leads me to 



86 



the opinion that far .more than one-half of 
these engines are running under-loaded. To 
speak more correctly, I would say that the ma- 
jority of engineers carry a higher pressure of 
steam than their work calls for. 

This may be equally true of other automatic 
engines, but I have found it so frequently the 
case in Corliss engine rooms, and so difficult 



Scale 50 




to convince engineers of their error, that I 
mention it here. The first card taken is gen- 
erally like the one I have constructed for the 
purpose of illustration. It will be seen that 
the fly-wheel is driving the piston during one- 
half of the time. The pressure of the steam on 
the piston is like a series of kicks, but it is not 



87 

best to let it kick so hard that it will kick back. 
The strain on the crank pin is greater, and the 
valves work harder while running in this 
way. 



CHAPTER IV. 

Another very important reason why the en- 
gines should not be operated in this manner, 
is the greatly increased cylinder condensation, 
owing to too great range of temperatures. 

The difference between the temperature of 
the initial pressure of this diagram and the ab- 
solute terminal pressure is about 140 degrees ; 
whereas if the steam had been lower, say 60 
pounds total, and the terminal about the same 
as the back pressure, the difference in the tem- 
peratures would have been only 80 degrees. 
It will be seen that there is a difference of 60 
degrees in favor of running with the lower 
steam pressure ; nearly as much as there- 
is between a winter and a summer day. 

I do not wish to be understood as advocat- 
ing low pressures, but would say — do not al- 
low a loop in the card while the engine is do- 
ing regular work. This may appear to many 
as an extreme case, but I have frequently 



88 



found the loop in the card from engines which 
were represented by engineers as heavily 
loaded. 

There are a great many old Corliss engines 
that have the packing rings set out by set 
screw T s against elliptic springs. I would ad- 
vise engineers who can't get anything better 
than this, to be extremely careful when setting 
out these screws. The best way is to stop the 
engine on the front centre, disconnect the main 
rod, and pull the piston to the back end ; then 
it can be ascertained by moving the piston 
back and forth when it is just right. It should 
be so easy that one man can readily move a 20 
inch piston in the cylinder. 

The Corliss engines of later make have a 
single packing ring, in small sections, let into 
a junk ring. This is a great improvement 
over the other, as it requires no setting out, 
and runs very satisfactorily ; but judgment 
should be used in setting up the screws for the 
purpose of centering the piston head. These 
are frequently set up so hard as to strain the 
junk ring out of round. If the junk ring nearly 
fills the bore of the cylinder (as it should), this 
strain causes it to bear very hard in these four 



8 9 

places, causing undue friction, and sometimes 
injury. 

The follower of this kind of piston is usually 
secured by large steel bolts. I have no doubt 
that many engineers have had serious trouble 
in starting these bolts. I remedy this by coat- 
ing the bolts with a mixture of Dixon's graphite 
and cylinder oil. This mixture is just the 
thing for pipe and other bolts about boilers, 
which are sure to stick unless something of 
this kind is used. 

We are frequently told by the newspapers 
that a very large proportion of the accidents 
in engine and boiler rooms are the result of 
carelessness, and right here they stop and 
leave the general reader with the impres- 
sion that it is the engineer in charge who 
is responsible. Carelessness and ignorance 
on the part of builders, and indifference 
on the part of owners, cause the greater part 
of the accidents. The engineer is gener- 
ally expected to get along with what he has, 
and very frequently cannot clean his boilers 
for lack of opportunity. I find in a copy of 
The Locomotive the monthly report of the inspect- 
ors of the Hartford Steam Boiler Insurance Co. , 



9° 

the following items : ' ' Cases of defective rivet- 
ing, 1,658 ; cases of deficiency of water, 6." 

Engineers and their assistants were faithfully 
attending to their boilers that month, and all 
the reports show about the some proportion. 

It is very much the same in the engine room, 
but we have no insurance company to publish 
records of defects that may exist there. If we 
had, there would be a large number of Corliss 
engines which would have to be stopped and 
have larger piston rods put in. There are a 
great many of these engines running that were 
built some twenty-five years ago (designed for 
a mean pressure of 30 pounds and a piston 
speed of about 350 feet,) that have been speed- 
ed up and the pressure increased. ^When one 
of these engines breaks down they usually 
send to the shop ; the wise man com.es and 
tells the manager that there was too much 
water in the boiler, and that the engine was 
blown up by too much water ; now the boiler 
is blown up by too little water, while it is very 
rarely the case that there is a grain of truth in 
either statement. 

Boilers thai are not strong enough to with- 
stand the pressure explode, and overloaded en- 







9* 

gines of faulty design and poor material are 
liable to accident, while a really first-class 
man is doing all in his power to prevent it 

The older engineers of the country will re- 
member when the original builders of the Cor- 
liss engine used cast-iron main shafts, and the 
numerous breaks caused by them ; and still we 
have cast iron cranks, cross-heads and valve 
arms. The spring of the cast-iron crank on a 
full loaded engine is quite appalling. Put the 
engine on the center, and work the valves by 
hand, and measure this deflection. Certainly, 
a stiffer crank is needed. 

The valve arms seldom break if the valves 
are properly oiled. Oiling the cylinder three 
or four strokes with the oil pump every ten or 
fifteen minutes will require nearly one gallon 
of oil per day, and still the valves will be dry 
nearly half the time. The Corliss oil-pump 
discharges one cubic inch at each stroke, and 
that single stroke does not oil the cylinder and 
valves any better than one drop ; therefore it is 
much better to have good automatic sight-feed 
cups for this purpose. 

The cast-iron cross-heads are seldom sound, 
and the manner in which they are suppoited is 



92 

very faulty. The latest patterns correct this, 
but there are a great many of the old style in 
use that can be improved by the engineer in 
the manner shown by the illustration. 

The nut under the cross head in Fig. i will 
not hold the cross head firmly, and long con- 




^> «y 



T£j 



4^ 



rjui m m rtrti 



^ 



, tn 



Fig. I Fig. 2 

tinued working will be likely to break the pis- 
ton rod. This movement of the cross head at 
the outer end cannot be seen, but it is there all 
the same. The support given by the bolts 
from the V, as shown in Fig. 2, are adjustable, 
and remedy this trouble. 






P^Ml 




